The invention relates to the manufacture of catalysts. The invention is a development of that described in an application of Cairns et al having common assignee and filed on the same date and entitled "Improvements in the manufacture of catalysts" which describes, inter alia, a method for use in the manufacture of a catalyst, which method comprises driving at a substrate surface a substantially atomic dispersion of a material which is catalytic, or which is a component of a catalytic system, to attach onto the substrate surface without agglomeration a major proportion of the atoms of the material impinging thereon.
Our aforesaid application further describes a specific method embodying the invention in which platinum is deposited onto a porous alumina substrate by ion beam sputtering.
There is a wide range of applications for catalysts such as may be manufactured by the said method. Some examples of such applications, in addition to hydrogenation, are in gas burners, isomerisation, applications currently using base metal to avoid the expense of noble metal catalysts, treatment of gaseous effluents, car exhaust treatment systems, and ignition devices.
In considering some of these applications, it is apparent that the choice of substrate can play an important part in optimising the performance of the catalytic system. A particular problem, for example, is the need for car exhaust treatment systems to withstand a severe environment and repeated thermal cycling throughout the operating lifetime of the system.
There are also indications that, for platinum, alumina is a particularly suitable substrate.
The present invention is concerned with providing for the catalytic material a substrate support which can be adapted to meet specialised operating criteria, such as, for example, a severe environment and thermal cycling.